1. Field of the Invention
The present invention relates to a tubular vibration-damping device having a bracket that is utilized as an automotive member mount for example.
2. Description of the Related Art
Conventionally, a tubular vibration-damping device including an inner shaft member, an outer tube member disposed on an outer peripheral side of the inner shaft member with a distance, and a main rubber elastic body connecting the inner shaft member and the outer tube member has been known.
Such a tubular vibration-damping device is utilized as a vibration-damping connector or a vibration-damping support such as an automotive engine mount, a member mount, a body mount, and a suspension bushing, in a state installed between attachment members that make up a vibration transmission system such as a power unit, a body, a member, and a suspension part.
In the tubular vibration-damping device, generally an inner shaft member is fixed to one attachment member by bolt-nut structure for example and an outer tube member is press-fitted into a mounting hole of a tubular bracket provided in the other attachment member when the device is installed between the attachment members that make up the vibration transmission system.
Incidentally, in recent years, it is considered to use an outer tube member made of synthetic resin for a tubular vibration-damping device instead of conventional member made of metal, for the advantage in reductions in weight and cost and the like.
However, since characteristics such as rigidity of synthetic resin are different from that of metal, a mere change of material was not able to meet the required characteristics such as load bearing and enduring capability.
In light of that, the present applicant previously disclosed a technique in Japanese Unexamined Patent Publication No. JP-A-2002-276714, the technique adopting an outer tube member made of synthetic resin, so as to avoid malfunction such as crack of an outer tube member which was likely to occur during press-fitting into a metal tubular bracket, thereby improving durability.
However, as a result of further consideration, the present inventor found a new problem in the structure with a particular outer tube member made of synthetic resin.